Publicação

Sustained macrophage reprogramming is required for CD8+ T cell–dependent long-term tumor eradication

Detalhes bibliográficos
Resumo:	Tumor-associated macrophages (TAM) exhibit a dual role in tumor progression and antitumor immunity. However, understanding the functional states and molecular mechanisms of antitumor TAMs remains a challenge. Herein, we show that intratumoral administration of a combination of agonists against TLR3 and CD40 [hereafter termed myeloid cell treatment (MCT)] reprogrammed TAMs in situ to adopt a protective antitumor phenotype in an orthotopic mouse breast cancer model, and that this led to tumor regression. Single-cell RNA sequencing of TAMs from different tumor stages and after MCT revealed a transient antitumor TAM phenotype, present at 12 hours after MCT and characterized by markers such as inducible nitric oxide synthase and CD38, which was replaced by TAMs coexpressing tumor-limiting and tumor-promoting features by 72 hours after MCT. Maintenance of antitumor TAMs required repeated MCT administration, and this promoted the activation of CD8+ T cells and long-term tumor eradication. Mechanistically, reactive oxygen species and TNF-α were pivotal in TAM-mediated tumor control. Our findings uncover the vulnerability of transient TAM reprogramming and show that it can be overcome by repeated MCT administrations to sustain efficient antitumor immune responses.
Autores principais:	Jardim, Carolina
Outros Autores:	Bica, Marta; Reis-Sobreiro, Mariana; Mota, Afonso Teixeira da; Lopes, Raquel; Ferreira-Pinto, Miguel Alexandre; Sousa, Neuza S.; Mensurado, Sofia; Boekhoff, Henning; Scolaro, Tommaso; Reugebrink, Maud; Gonçalves-Sousa, Natacha; Kubo, Hiroshi; Leites, Elvira; Morais, Vanessa A.; Silva-Santos, Bruno; Barbosa-Morais, Nuno; Serre, Karine
Ano:	2025
País:	Portugal
Tipo de documento:	artigo
Tipo de acesso:	acesso aberto
Instituição associada:	Universidade de Lisboa
Idioma:	inglês
Origem:	Repositório da Universidade de Lisboa

Descrição
Resumo:	Tumor-associated macrophages (TAM) exhibit a dual role in tumor progression and antitumor immunity. However, understanding the functional states and molecular mechanisms of antitumor TAMs remains a challenge. Herein, we show that intratumoral administration of a combination of agonists against TLR3 and CD40 [hereafter termed myeloid cell treatment (MCT)] reprogrammed TAMs in situ to adopt a protective antitumor phenotype in an orthotopic mouse breast cancer model, and that this led to tumor regression. Single-cell RNA sequencing of TAMs from different tumor stages and after MCT revealed a transient antitumor TAM phenotype, present at 12 hours after MCT and characterized by markers such as inducible nitric oxide synthase and CD38, which was replaced by TAMs coexpressing tumor-limiting and tumor-promoting features by 72 hours after MCT. Maintenance of antitumor TAMs required repeated MCT administration, and this promoted the activation of CD8+ T cells and long-term tumor eradication. Mechanistically, reactive oxygen species and TNF-α were pivotal in TAM-mediated tumor control. Our findings uncover the vulnerability of transient TAM reprogramming and show that it can be overcome by repeated MCT administrations to sustain efficient antitumor immune responses.